Method for detecting a defect on a surface of a tire

Abstract

A method for detecting a defect on a surface of a tire includes automated steps of: calculating values of a gradient of a plurality of texture parameters from an image of the surface of the tire, determining an image of the gradient, and thresholding of the image of the gradient to obtain a thresholded image.

The invention claimed is: 
     
       1. A method for detecting a defect on a surface of a tire, the method comprising:
 automatically calculating, using a computer, values of a gradient of a plurality of texture parameters from an image of the surface of the tire; 
 automatically determining, using the computer, an image of the gradient; 
 automatically thresholding, using the computer, the image of the gradient to obtain a thresholded image; and 
 displaying the thresholded image, wherein the plurality of texture parameters comprises at least five texture parameters. 
 
     
     
       2. The method according to  claim 1 , wherein the image of the surface of the tire is an image of an inner surface of the tire. 
     
     
       3. The method according to  claim 1 , further comprising using a laser system to automatically acquire the image of the surface of the tire by laser triangulation. 
     
     
       4. The method according to  claim 1 , wherein the computer calculates the values of the gradient in a selection of pixels of a part of the image of the surface of the tire. 
     
     
       5. The method according to  claim 1 , further comprising automatically calculating, using the computer, a grey-level gradient in the image of the surface of the tire. 
     
     
       6. The method according to  claim 1 , wherein the thresholding is performed by the computer using a hysteresis process. 
     
     
       7. The method according to  claim 1 , wherein the plurality of texture parameters consists of five texture parameters. 
     
     
       8. The method according to  claim 1 , wherein the plurality of texture parameters comprises Haralick parameters. 
     
     
       9. The method according to  claim 1 , wherein the plurality of texture parameters comprises a local binary pattern. 
     
     
       10. The method according to  claim 1 , wherein the plurality of texture parameters comprises 25 texture parameters. 
     
     
       11. A computer-readable storage medium storing a program that when executed by a computer causes the computer to perform a method for detecting a defect on a surface of a tire, wherein the method includes:
 automatically calculating values of a gradient of a plurality of texture parameters from an image of the surface of the tire; 
 automatically determining an image of the gradient; 
 automatically thresholding the image of the gradient to obtain a thresholded image; and 
 displaying the thresholded image, wherein the plurality of texture parameters comprises at least five texture parameters. 
 
     
     
       12. A method for detecting a defect on a surface of a tire, the method comprising downloading to a computer, via a telecommunications network, coded instructions that when executed by the computer cause the computer to:
 automatically calculate values of a gradient of a plurality of texture parameters from an image of the surface of the tire, 
 automatically determine an image of the gradient, 
 automatically perform a thresholding process on the image of the gradient to obtain a thresholded image, and 
 display the thresholded image, wherein the plurality of texture parameters comprises at least five texture parameters. 
 
     
     
       13. An installation for detecting a defect on a surface of a tire, the installation comprising a computer programmed to:
 automatically calculate values of a gradient of a plurality of texture parameters from an image of the surface of the tire, 
 automatically determine an image of the gradient, 
 automatically perform a thresholding process on the image of the gradient to obtain a thresholded image, and 
 display the thresholded image, wherein the plurality of texture parameters comprises at least five texture parameters. 
 
     
     
       14. The installation according to  claim 13 , further comprising a laser system that automatically acquires the image of the surface of the tire.